A multi-scale modeling approach for simulating crack sensing in polymer fibrous composites using electrically conductive carbon nanotube networks. Part I: Micro-scale analysis

摘要

This is the first of a two-paper series describing a multi-scale modeling approach developed to simulate crack sensing in polymer fibrous composites by exploiting the interruption of electrically conducive carbon nanotube (CNT) networks. The approach is based on the finite element (FE) method. FE models at three different scales, namely the micro-scale, the meso-scale and the macro-scale have been developed using the ANSYS PDL environment. In the present paper, the micro-scale analysis is described. In the micro-scale, two representative volume elements (RVEs) have been developed: a RVE of a CNT/polymer for validating the computation of the effective electrical conductivity of the nanocomposite and a RVE of a CNT/composite for evaluating the effect of crack presence on the effective electrical conductivity. In the CNT/composite RVE, carbon fibers and glass fibers have been modeled. The computed effective electrical conductivity of the CNT/polymer shows a very good agreement with experimental results from the literature, something which validates the proposed electrical modeling approach. The model of the CNT/composite shows a large sensitivity on the presence of the crack. The model with the carbon fibers shows a more homogeneous electrical response compared to the model with the glass fibers which is due to the conducive nature of carbon.